The present invention relates to nutrient compositions for athletes, to be used in connection with training and competition, as well as to the methods for producing and using those compositions. In particular, the invention relates to an orally ingestible palatable blend which provides substantially all of the nutritional, carbohydrate, and energy requirements of an athlete under conditions of physical stress, without interfering with fluid absorption or causing gastrointestinal disturbances. The invention additionally relates to a new method of preparation of solid nutrients which allows for rapid and complete dissolution of the final blend in tap water under ordinary use conditions.
The use of sport drinks to satisfy various requirements of athletes during training and competition is known. Known drinks are used to provide energy and replace lost electrolytes and nutrients. Sport drinks that are currently on the market generally fall into one of four categories. The first category includes sports drinks that contain only sugar and water. The sports drink marketed under the name "Max" by Coca Cola Company is an example. That drink contains a five percent (5%) solution of dextrose and malto-dextrin.
The second category includes sports drinks that consist of sugars, plus some electrolytes, in water.
The third category consists of sport drinks that contain sugars, some electrolytes, and some vitamins. The sports drinks "Gatorade" (marketed by Stokely-Van Camp, Inc.) and "Exceed" (marketed by the Ross division of Abbott Laboratories) are examples. Gatorade contains a six percent (6%) solution of sucrose and glucose, 220 mg of sodium and 50 mg of potassium per serving and some vitamin C. "Exceed" has glucose polymers and fructose, 280 mg of sodium, 430 mg of potassium, 380 mg chloride and other electrolytes in every 8 ounce serving.
The fourth category includes sports drinks consisting of sugars, some electrolytes, some vitamins. and some minerals. The sports drinks "Body Fuel 450" (marketed by Vitex Foods, Inc.), and "Pripps Plus" (marketed by Aktiebolaget Pripps Bryggrier) are examples.
Although not directed to the particular nutritional needs of athletes, U.S. Pat. No. 3,697,287 to Winitz discloses what is said to be a palatable food composition which contains all of the essential amino acids, essential minerals, and carbohydrates. The invention disclosed therein claims to achieve palatability by (a) minimizing amino acids or amino acid derivatives which contain sulfhydryl (SH) groups; (b) minimizing amino acids or their derivatives whose taste is incompatible with the flavor of the mixture of the other ingredients; and (c) minimizing the use of amino acids or their derivatives that are not of sufficient purity. Winitz also discloses a pH dependence of the flavor of certain ingredients. That invention also discloses the interchangeability of nutritional equivalents of amino acids, for example, the esters, amides, and salt derivatives thereof or precursors such as peptones or peptides. Inclusion of these can result in slower absorption and consumption of greater amounts of digestive energy compared to the composition of the present invention, factors of great importance to a high performance athlete. Other disadvantages of the use of the Winitz composition in the context of training and competition can be understood from the following disclosure.
None of the prior art drinks can be used as the exclusive source of nutrition during periods of training or competition, as none of the available sports drinks will provide for substantially all of the nutritional requirements of the body under stress. For the purposes of this invention, a "stress" condition exists when an individual's metabolic rate exceeds approximately 500 kcal per hour as a result of physical exertion, or, alternatively, when through sustained exertion an individual maintains a pulse rate in excess of 125 beats per minute for a period of 90 minutes or more. Additional nutrient sources are needed during long training sessions and competitions. As well as failing to provide for substantially all of the athlete's nutritional needs, known sports drinks are attended by a number of additional disadvantages.
One disadvantage of prior art formulations is the generally low gastrointestinal tolerance. Tolerance can be described as the capacity of the gastrointestinal tract to ingest and digest food. The proper balance of amino acids, carbohydrates, electrolytes, vitamins, minerals and trace elements creates the proper lumenal environment (e.g., osmolality, etc.) to prevent the flow of water and electrolytes into the lumen of the small bowel which may cause distention of the bowel, thus creating pressure, pain and cramps from increased peristalsis. Prior art products generally have a high osmotic load which creates an increasing fluid volume in the large bowel, causing diarrhea. Diarrhea causes dehydration and magnifies the electrolyte imbalance which has a catastrophic impact on athletes undergoing the stress of training and competition.
Presently available sources of nutrition for athletes are additionally not optimized to provide maximal rates of absorption. Foods that are slowly absorbed during digestion do not provide the body with immediate energy, whereas nutrients which quickly cross the mucosal membranes into the blood provide more immediate energy. Moreover, sports drinks and foods which require large amounts of digestive energy will not be optimally beneficial to the athlete during training and competition. During exercise, most of the blood is shunted or diverted from the gastrointestinal tract to the muscle groups performing the exercise. Hence, any diversion of blood back to the gastrointestinal track for digestion, which will result, for example, from a diet comprising fats or polypeptide protein, could reduce the blood available to the muscles, thereby diminishing performance. On the other hand, as a result of sustained exertion and physical stress, digestion of complex materials may proceed too slowly to provide adequate nutrition to the athlete during such exertion.
Another problem athletes face is familiarity with, and reproducibility of, their diet. It is well known that if an athlete eats something during training or competition that his body is not used to, performance will suffer.
Another important consideration in the design of a complete nutrient composition for athletes is the effect of stress upon the breakdown of muscle protein. Under conditions of stress there is an increased use of amino acids from muscle tissue as an energy source, and an increased percentage of total calories are supplied by the direct oxidation of the branched-chain amino acids leucine, isoleucine and valine. See, e.g., K. J. Fchott, J. Jehrmann, U. P:otter, V. Neuhoff "On the Role of Branched-Chaim Amino Acid in Protein Metabolism of Skeletal Muscle", Journal of Z Naturforsch, May-June 1985, line 40, pgs. 427-437; S. F. Lowry, G. D. Harowitz, D. Rose, M. F. Brennan "Influence of Nutritional Status on Exertion Induced Forearm Amino Acid Metabolism in Normal Man", Journal of Surgical Research, May 1984, Vol. 36, pgs. 438-445; D. Horst, N. D. Grace, H. O. Conn, E. Schiff, S. Schenker, A. Viteri, D. Law, C. E. Atterbury "Comparison of Dietary Protein With an Oral, Branched-Chain Enriched Amino Acid Suplement in Chronic Portal - Sestemic Encephalopathy", Journal of Hepatology, March-April 1984, Vol. 4, pgs. 279-287; A. E. Harper, R. H. Miller, K. P. Block "Branched-Chain Amino Acid Metabolism", Annual Review of Nutrition, 1984, Vol. 4, pgs. 409-454; and F. B. Cerra, J. E. Macuski, E. Chute, N. Newer, K. Teasley, J. Lysne, E. P. Shronts, S. N. Konstantinides "Branched-Chain Metabolic Support, a prospective, Randomized, Double Blind Trial in Surgical Stress", Annals of Surgery, March 1984, Vol. 199, pgs. 286-291. Urinary excretion of nitrogen, resulting from the breakdown of muscle protein, is high during conditions of stress. Branched-chain amino acids exert a nitrogen retention effect when ingested during conditions of stress.
An additional disadvantage of the presently available sports drinks is that few have a palatable taste. Taste or palatability is an important parameter for a sports drink or nutrition source. Excellent taste is not easily achieved for a sports drink or nutrition source for an athlete as the sense of taste changes with the metabolic state of the individual.
Furthermore, standard methods for the preparation of known solid nutrient blends are inadequate for the more complex blends necessary for a complete nutrient composition for athletes. Standard methods of preparation of solid chemical blends typically involve simple weighing and blending steps. As an example, the most straightforward standard method of preparation of a solid chemical blend is a procedure involving the individual weighing of each of the raw materials followed by a simple mixing or milling of all of the solids together under low mixing speeds for a defined period of time. As the complexity of the composition increases, however, it has been discovered that more steps and unique methods of preparation are required. It was determined that the more straightforward methods for the preparation of solid nutrient blends could not achieve a final blend which could be rapidly and completely dissolved in tap water under ordinary use conditions. The failure of these standard methods was caused mainly by the insolubility of several amino acids, particularly hydrophobic and aromatic amino acids, e.g., leucine, valine, phenylalanine, tryptophan, tyrosine, aspartic acid and glutamic acid.